Reporter Jessica Golloher tells NPR's Newscasts the dissenters included "anti-corruption blogger Alexei Navalny, TV host Ksenia Sobchak, leftist Sergei Udaltsov and activist Ilya Yashin".
They're among a group of protesters who say corruption and a tightly controlled political system allow Putin to run the country. Russian leaders deny the charges. Reuters reports Udaltsov ignored his summons and showed up at the rally anyway.
The rally was okayed ahead of time by Moscow authorities, which means people arrested for unauthorized demonstrating won't face stiff new fines. Putin signed a law last week that increased the penalties by 150-fold, notes CBS.
Despite the fines and questioning of political dissenters, Putin issued remarks, saying that different points of view can now be heard within Russia and that everyone needs to work together to create a desirable society, according to the Washington Post. His statement came on the public holiday, Russia Day. This honors the day in 1990 when the Russian republic declared its own sovereignty, months before the Soviet Union collapsed.